1. Field of the Invention
The present invention relates to a method for manufacturing an invisible trademark zipper. More particularly, the present invention relates to a method for manufacturing a trademark zipper capable of precisely presenting trademarks, patterns, characters, or marks thereon when two complementary halves are zipped.
2. Description of the Prior Art
Invisible trademark zipper is known in the art. FIG. 1 illustrates a typical view of manufacturing a prior art invisible trademark zipper. As shown in FIG. 1, patterns, characters, or marks 10, which are divided into two complementary halves 101 and 102, are printed, dyed, or weaved on two sides along the longitudinal central line 201 of the continued yard strip 20. Before transferring the yard strip 20 into a weaving machine (not shown), the yard strip 20 is cut into two symmetric pieces along the central line 201 using a cutting knife 30, thereby forming two zipper strips 202 and 203. Thereafter, the two separated zipper strips 202 and 203 are transferred into the weaving machine. In the weaving machine, two spiral zipper teeth 401 and 403 (both made of Nylon) are weaved onto respective inner fringes of the two separated zipper strips 202 and 203 by the dragging force provided by the weaving machine and two sets of weaving needles 501 and 502. A pull tab (not shown in this figure) is then installed thereon to gear up the two spiral zipper teeth 401 and 403, thereby presenting a complete pattern, character, or mark by combining the two complementary halves 101 and 102 on the respective zipper strips 202 and 203.
However, the above-mentioned prior art method has a drawback. In practice, since the two zipper teeth 401 and 402 are made of Nylon and are spiral, pitch between two adjacent teeth of each of the zipper teeth is not constant. The pitch may be compressed or extended by the outer force because of the flexible nature of the zipper teeth 401 and 402. Further, during the process of weaving the two zipper teeth 401 and 402 onto the zipper strips 202 and 203 by the weaving needles 501 and 502, the dragging force applied on zipper teeth 401 and 402 from the weaving machine deteriorates the inconsistence of the teeth pitch of respective zipper teeth. As shown in FIG. 2, the inconsistence between two zipper teeth results in pattern shift (as indicated by the xe2x80x9cKxe2x80x9d), which is not pleasing to eye.
Consequently, there is a need to provide an improved method for manufacturing an invisible trademark zipper to solve the above-mentioned problem.
The main objective of the invention is to provide a method for manufacturing an invisible trademark zipper.
According to the claimed invention, a method for manufacturing an invisible trademark zipper is provided. The method comprises (1) transferring a continued yard strip printed or weaved thereon with complementary halves of a pattern, a character, or a mark facing down into a weaving machine; (2) synchronizing two zipper teeth by passing the two zipper teeth through a teeth driving device by which tooth-by-tooth feeding and consistent teeth pitch can be carried out, thereafter transferring the two zipper teeth together with the continued yard strip into the weaving machine; (3) sewing the two zipper teeth on predetermined positions at two sides of a longitudinal central line of the continued yard strip near the complementary halves of a pattern, a character, or a mark by using two sets of needles; (4) using a cutting device to cut the continued yard strip into two symmetric pieces along the longitudinal central line of the continued yard strip, thereby forming two zipper strips having respective zipper teeth and foldable fringes; and (5) folding the two foldable fringes of the two zipper strips. By folding the two zipper strips and the use of a pull tab, the zipper teeth are engaged with each other to completely present the pattern, character, or mark on the two zipper strips.
Other objects, advantages and novel features of the invention will become more clearly and readily apparent from the following detailed description when taken in conjunction with the accompanying drawings.